package com.yb.util;

import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @author tian
 *
 */
public class CharSetUtil {

 /**
  * 解码 Unicode \\uXXXX
  * @param str
  * @return
  */
	 public static String decodeUnicode(String str) {
		  Charset set = Charset.forName("UTF-16");
		  Pattern p = Pattern.compile("\\\\u([0-9a-fA-F]{4})");
		  Matcher m = p.matcher( str );
		  int start = 0 ;
		  int start2 = 0 ;
		  StringBuffer sb = new StringBuffer();
		  while( m.find( start ) ) {
			   start2 = m.start() ;
			   if( start2 > start ){
				    String seg = str.substring(start, start2) ;
				    sb.append( seg );
		   }
		   String code = m.group( 1 );
		   int i = Integer.valueOf( code , 16 );
		   byte[] bb = new byte[ 4 ] ;
		   bb[ 0 ] = (byte) ((i >> 8) & 0xFF );
		   bb[ 1 ] = (byte) ( i & 0xFF ) ;
		   ByteBuffer b = ByteBuffer.wrap(bb);
		   sb.append( String.valueOf( set.decode(b) ).trim() );
		   start = m.end() ;
		  }
		  start2 = str.length() ;
		  if( start2 > start ){
			   String seg = str.substring(start, start2) ;
			   sb.append( seg );
		  }
		  return sb.toString() ;
	 }
 
 public static void main(String[] args) {
  System.out.println( decodeUnicode("\u5965\u96f7\u5e03\u6d1b"));
 }
}